Inspection 'failures' before Ayrshire derailment on 27 January 2009

From the BBC^» British Broadcasting Corporation - home page):

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Network Rail has been blamed for a catalogue of inspection failures over a bridge collapse which caused a freight train to derail in Ayrshire.
The train, which was carrying kerosene, gas oil and diesel, came off the rails south of Stewarton on 27 January 2009.
The Rail Accident Investigation Branch said corrosion in the bridge's girders meant it could not support heavy loads.
Its report criticises Network Rail's maintenance regime for the bridge and says corrosion went unidentified.
Six of the 10 wagons came off the rails during the incident and some caught fire, causing flames to shoot 50ft into the air.
Power lines were also brought down and the nearby A735 was closed. It took the emergency services several hours to bring the fire under control.
The resultant leakage of fuel contaminated local waterways, causing harm to wildlife.
In the immediate aftermath, it was thought that the derailment had caused the bridge to collapse.
But in its report, the Rail Accident Investigation Branch (RAIB^▸ ) said the bridge - referred to as bridge 88 - had failed under the weight of the train, causing it to derail.
The report states: "The immediate cause of the derailment was the collapse of the bridge that followed the catastrophic structural failure of its east and centre main girders.
"Heavy corrosion had so significantly weakened these main girders that they were no longer able to carry the loading from trains that were permitted to run over the bridge."
The report criticises Network Rail's maintenance regime for the bridge and said "hidden corrosion" had gone unidentified.
It states that "no arrangements had been made to inspect the hidden parts of the east and centre main girders" where the heavy corrosion had occurred.
Corroded parts of the bridge were "not fully repaired" when the bridge was waterproofed in 1987.
The report also states that the bridge superstructure was not re-painted when the waterproofing work was done, or afterwards.
The RAIB also said there had been a "lack of action" after corrosion was highlighted in an urgent defect report in October 2003.
It recommends that Network Rail undertakes "checks and intervention action" on other bridges "that may be at risk because of similar hidden corrosion issues or erroneous assessment findings".
The operator of Britain's rail infrastructure is also urged to improve its "methods and processes for the examination of hidden critical parts of structures" and its management of the information used for making decisions about the structural safety of its bridges.
Network Rail said that since the crash it had carried out inspections on 575 bridges of similar design throughout the UK^▸ - 129 of which were in Scotland.
A spokesman said: "This was a serious incident which we have investigated thoroughly alongside the RAIB investigation.
"Both investigations have concluded that the main cause of the incident was the condition of the centre main girder supporting the bridge deck which failed under the weight of the loaded freight train.
"Although the bridge had previously been inspected (on 25 February 2008), the style of construction of the bridge meant this internal main girder was not open to inspection.
"Network Rail reacted immediately by carrying out precautionary checks on all bridges of a similar design.
"Of these, to establish confidence in potentially hidden parts, 575 have been inspected by engineers. No bridges have been found in a condition similar to that of the bridge at Stewarton.
"As a result of this incident, we have reviewed the way we examine bridges of a similar style.
"We have made changes to our inspection procedures so that bridge inspectors are required to expose hidden critical elements of the bridge during examination."

The full RAIB report is available on their website.